function C4(varargin)
%**********************************************************************
%*** * Actuator Module
%*** * Reserved C(3510) locations are 900-999
%*** *
%*** * MODIFICATION HISTORY
%*** * 13-07-2012 T Jelliffe   Added in the empty functions
%*** *
%**********************************************************************


  global bcom_1; if isempty(bcom_1), bcom_1=zeros(1,3510); end;
  %% common c(3510);
  %% common bcom_1(3510);

  %*** INPUT FROM EXECUTIVE

  % equivalence(bcom_1(0052),crad) ::;
  % equivalence(bcom_1(2000),t) ::;

  %*** DIAGNOSTICS

  % equivalence(bcom_1(1602),psivgx) ::;
  % equivalence(bcom_1(1603),thtvgx) ::;
  % equivalence(bcom_1(1604),blon) ::;
  % equivalence(bcom_1(1605),blat) ::;
  % equivalence(bcom_1(1607),dvbi) ::;
  % equivalence(bcom_1(1608),psivigx) ::;
  % equivalence(bcom_1(1609),thtvigx) ::;
  % equivalence(bcom_1(1610),baltft) ::;
  % equivalence(bcom_1(1203),alphax) ::;

  % PSIVGX = G Heading angle from north - deg
  % THTVGX = G Flight path angle from horizontal - deg
  % BLON = G Vehicle longitude - rad
  % BLAT = G Vehicle latitude - rad
  % DVBI = G Speed of vehicle wrt inertial frame
  % PSIVIGX = G Heading angle of inertial vel vect - deg
  % THTVIGX = G Flight path angle of inert vel vec  - deg
  % BALTFT = G Vehicle Altitude - ft

  %*** INPUT FROM OTHER MODULES

  % equivalence(bcom_1(1606),balt) ::;
  % equivalence(bcom_1(1613),dvbe) ::;
  % equivalence(bcom_1(0900),orbalt) ::;

  % BALT= I/O Vehicle altitude = m
  % DVBE= I/G Geographic speed - m/s
  % ORBALT = I Target orbital altitude - m

  %*** OUTPUT TO OTHER MODULES

  %      EQUIVALENCE (C(xx),xxx)

  % ALPHAX = O Angle of attack - deg

  %      PRINT *,'Orbital Altitude:', ORBALT
  if(t > 60.0)
  thtvgx = 88.;
  end;
  if(t > 80.0)
  thtvgx = 85.;
  end;
  if(t > 90.0)
  thtvgx = 80.;
  end;

  return;
end %subroutine c4